Piston skirt expander



.,1. -KoUFeiMsKY PISTON SKIRT EXFANDER Filed Marh 26, 1955 Patented Dec. 17, 1935 uNlTlazDv STATES lniTliiNr OFFICE y 2,024,457 PIs'roN SKIRT EXPANDER J ames Kourimsky, Chicago, Ill.

Application March 26, 1935, Serial No. 13,090

3 Claims.

bination of parts in an expander device for the slitted skirt portion of a trunk piston of a simple, compact and economical form, adapted to resiliently act on the slitted skirt portion of the piston, and by means of which the extent of expansion of the piston skirt can be readily and effectively attained so as to regulate the frictional contact between the piston and the inner wall cf an engine cylinder, allY as will hereinafter more fully appear. e

In the accompanying drawing:

Fig 1 is a centralV sectional elevation on line I--I Fig. 2 of a trunk piston to which this invention is applied.

Fig. 2 is a horizontal section of same on line 2-2 Fig. 1.

Fig. 3 is an enlarged detail section on line 3-3 Fig. 1.

Fig. 4 is a detail sectional elevation on line 4--4 Fig. 3.

Fig. 5 is a detail sectional 5 5 Fig. 4.

Fig. fis a side elevation of a modified form of the device.

Fig. 7 is a detailv section of same online 1-1 Fig. 6. Y

Like reference numerals indicate like parts in the different views.

This invention is shown in the drawing as applied to a piston of the trunk type,V the skirt portion l of which is 'rendered expansible by a elevation on line longitudinal slot 2, usually of T-shape as shown.

In this improvement the skirt portion 2 is formed with receiving orices 3 in adjacent relation to the opposed margins of the slit 2 thereof for holding engagement with the attaching pins or studs of the device for producing a resilient expansion ofthe piston skirt and the adjustable control of the extent of such expansion as the judgment of the operator Vmay suggest. Said device comprising a detail construction of parts, as follows: Y Y Y ,Y

Said device comprising a pair of substantially counterpart blocks or heads 4 and 5 arranged in opposedV relation and Vof ,an approximately rectangular shape, with an inner face of each head provided with a xed or integrally formedY eiiect the desired regulation of the parts.

attachingrpin or stud 6 adapted to engage in lan aforesaid hole or orice 3 of the piston skirt to hold the device in proper operative position during actual use.

In the preferred form of this invention shown 5 in Figs. 1 to 5 inclusive, the heads 4, 5, 'are formed with pairs Vof socket recesses 4 and 5' in their opposed faces for the reception of end portions of a pair of compression springs 1 of the spiral type,V the resilient tendency of which i. is to force the heads 5, apart, to in turn cause a corresponding resilient expansion of the piston skirt l. Y

Intermediate of the aforesaid socket recesses A', 5', the heads 4 and 5 are formed with aligned 15.

. passages in parallel relation to said socket recesses, .adapted to receive the shank portion of a screw bolt 8, the fixed head 9 of which has bearing on an outer and remote face of one head or block and is held from independent turning movement by contact of said bolt head with a i xed rib I0 on the head or block.

The adjustable nut Il has bearing on the outer and remote face of the companion head or block andv may be held from accidental turning movement during actual use by any ordinary nut locking provision.

With the above described construction, the device can be adjusted as required to regulate the range of expansion of the piston skirt I under the influence of 'the springs 'l to attain the Vdesired resilient contact of the piston skirt with` the inner wall of the engine cylinder with arr` avoidance of wear due to an excessive expansion of the springs 1 when not restricted by means 35; controlling the resilient expansion thereof.

In the modified form of the invention shownr` in Fig. 6 and 7, a single expansion spring 1 is. arranged at the center of the pair of heads or blocks in a manner similar to that described in connection with the preferred Vform of the invention, with a pair of screw bolts 8 arranged at opposite sides 'of said-spring and adapted to Having thus fully described my invention, what YI claim as new, isz- 1. The combination with a trunk piston, the skirt portion of which is slitted for expansion purpose, and in which the margins of the slit are provided with receiving orifices, a pair of expander heads each provided with an attaching stud for engagement in a receiving orifice of the piston skirt, and with socket recesses in their opposed faces, expansion springs arranged in 5v5 'said socket recesses, and an adjustable screw bolt extending through said heads and adapted to regulate the degree of expansion between said heads and corresponding expansion of the piston 5 skirt.

2. A trunk piston as specied in claim 1 wherein the pair of expander heads are each formed With a pair of socket recesses in spaced relation, and a single regulating screw bolt extending through the pair of heads midway be# tween the pair of socket recesses.

3. A trunk piston as specied in claim l, wherein one of the pair of expander heads is provided with an upstanding rib having adjacent relation to the xed head of the adjusting screw bolt and adapted to hold the same from a turning movement in actual use of the piston.

JAMES KOURIMSKY. 

